What factor allowed many more African Americans to pursue careers in fields like medicine and law?

In 1073, the fight over who gets to choose bishops was between pope gregory vii and king henry the iv. t or f

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.

Astorage company rents square storage units by the area of the unit. which graph shows the relationship between the area (x) of a storage unit and the length of its side (y)?